Casting method



F. HACHMANN CASTING METHOD. APPLICATION FILED APR-2, 1917. RENEWED MAY13. I920.

Patented 0ct.26, 1920.

UNITED STATES PAT NT oFF'IcE.

FREDE ICK HACHMANN, or ST. LoUIS, MIssoURI, ASSIGNOR, BY DIRECT ANDMESNE ASSIGNMENTS, or ONE-FOURTH TO JOHN A. DOWDALL AND oN'E-FoURTII ToBER.- NARI) GREENSFELLDER; BOTH on ST. LOUIS, MISSoURI, AND ONE-HALF TONA- TIoNAnME'I'AL DIE MOLD coMrANY, or ST. LOUIS, MISSOURI, AcoRroRArIoN or MISsoURI.

CASTING METHOD.

Application filed April 2, 1917, Serial No. 159,236. Renewed May 13,1920. Serial No. 381,192.

To all whom it may concern:

Be it known that I, FREDERICK HACH- MANN, a citizen of the-UnitedStates, and residing at St. Louis, Missouri, have invented the new anduseful Improvement. in Casting Methods, of which the following is aspecification.

This invention relates to a casting method and apparatus, and moreparticularly to a method and apparatus for casting metals, Tuch asbrass, bronze and other copper aloys.

In casting metals of the higher melting points, it is the presentpractice touse sand or loam molds which are, of course, vented in orderto insure the escape of gases, such as air, etc. With such molds, theremust necessarily be allowed a good deal of draft in order to permitwithdrawalof the pattern from the mold, and there must also be allowedconsiderable finishin order to take care of pits and blowholes. Theresult therefore, is that the casting is necessarily considerablyoversize, which. means waste in metal, fuel, labor and the incidentalexpense of machining.

Various attempts have been made to use metal molds in order toobviate'the draft and finish, and the resultant wastage always gresentin using sand and loam molds.

uch attempts have, however, been in the main, unsuccessful, exceptwithmetals of low fusing points, which permit the application of pressureToform what are called die castings. It is, however, impractical to castmetals of the higher melting points, such as brass, bronze, and otheralloys of copper, in metal molds; this difliculty is particularly due tothe impossibility of withdrawing the air and other gases from the moldcavity during the casting operation,

so that the resultant casting will be full of pits and blowholes.Moreover, these higher melting point. metals will adhere or solder tothe mold, so that the separation of the casting from the mold isdiflicult and often an impossibility, except where the casting Q1 mold,or'both, are destroyed.

Some of the objects of this invention, therefore, are to provide acasting method and apparatus in which the withdrawal of the air andother gases from the mold cavity is Insured, and in which the walls ofthe mold cavity are treated in such a manner as to prevent adhesion ofthe material, to cast,

' to the mold.

Further objects will appear from'the detail description taken inconnection with the accompanying drawings, in which:

Figure 1 is a plan of a mold embodying this invention;

Fig. 2 is an elevation of-one of the mold sections, the view beingtaken. on the line 2-2, Fig. 1;

liig. 3 is a section on the line 3 -3, Fig. 1; an

Fig. 4 is a reduced perspective of the cast- -ous points, but theseventing passages are constructed to avoid flowing of the cast ma terialtherein. The mold cavity walls are treated to prevent adhesion theretoof the material to be cast. This is effected by applying tothe moldwall, a lubricant, such as a high flash point oil. In order to maintainthis lubricant on the cavity walls, there are employed a series oflubricant conducting passages or channels, which deliver the lubricantat numerous points on the cavity walls. The lubricant is maintained in asource of supply which contains a retaining vehicle holding thelubricant by an absorbent action, so that the lubricant will bedelivered at avery low pressure to the cavity walls; These passages, asis the case of the venting passages, are made small enough to avoidflowin of the cast-material therein. As the lubricant is necessarilysomewhat volatile even where a high fiashpoint oil is be placed inalined relation by dowels 1 in v one section, cooperating with holes 5in the other section. Each mold section has formed therein, one or moreparts of mold cavities 6, of a shape to form the desired casting. Inorder to furnish a gate, the sections are recessed as shown at 7 I Themold sections are cut to form a channel 8, extending along the mold, andfrom these channels extend branches 9, these branch channels 9 extendingupwardly, and being arranged along the mold cavity, onehalf of eachbranch being formed in each section of the mold, as shown in Fig. 2.Connecting the mold cavity with the channels 8 and 9, are a seriesof'venting passages 10, each cut in one-half of the mold section, asshown in Fig. 2. These venting passages 10 are small and form, in fact,capillary passages, in that, while they permit discharge of gases,they-do not permit flow of the metal therein, to more than aninfinitesimal amount. These passages 10 are for the purpose ofwithdrawing the air from the mold during the casting operation, and inorder to obtain the best results, these passages referably incline orextend downwardly rolm the mold cavity to the outlet channe s.

Arranged laterally of and extending along a mold cavity, are a pair ofpockets 11, which are filled with a lubricant retaining vehicle adaptedto absorb and retain the lubricant. A material which is found tosatisfactorily answer this purpose is a granular porous carboncontaining no graphite, and in pieces about the size of a match head.The mold cavity is connected with these pockets by means of capillarylubricant conducting passages, which are cut in the faces'of the blocksbefore they are' put together. In order to obtain a gravity flow, thepassages 12 are preferably inclined or extend downwardly from thepockets to the mold cavity. It will be noted that both the ventingpassages 10 and the lubricant conducting passages 12, enter the moldcavity at numerous points, and that the venting passages are, therefore,closely adjacent the lubricant conducting passages.

It will also be noted that, as is .the case with the venting passages10, the lubricant conducting passages 12, are'of small diameter,

. so as to avoid flowing of the metal therein.

ing connected by terminals 14, to a source of current. In order toretain this element in place, plates 15 are provided, which are screwedto the mold by screws 16. It will, of course, be understood that theresistance heating element 13 is suitably insulated from the mold andthe mold section, and from the plate 15.

When a casting is to be made, the filling in the pockets 11 is saturatedwith a lubricant, such as a high flash point mineral oil, and the wallsof the mold cavity have also preferably applied thereto, in any suitablemanner, a film of this oil. It will, of course, be understood that themold has first been heated up to a sufficiently high temperature bycurrent traversing the heating element. The metal is now poured into themold in the usual manner, and as it flows into the mold cavity, the airand gases escape through the venting passages 10. Moreover, anyvolatilized oil'will escape through these same venting passages 10, astheir position close to the lubricant conducting passages, and theirnumerous outlets to the surface of the mold, will quickly insure thewithdrawal of any gas which may be formed or which may be present duringthe casting operation. The casting will, therefore, be free from pitsand blowholes. The film of oil on the mold cavity walls, will preventadhesion of the metal to the mold, and the supply of lubricant to themold cavity walls is continually supplemented by the lubricantconducting passages 12 leading from the sources of lubricant supply inthe pockets 11. Adhesion of the metal to the mold is, therefore,avoided. Furthermore, the presence of this lubricant has the tendency togive a smooth finish surface on account of the formation of carbon, sothat smooth castings are obtained. I

It is obvious that various changes may be made in details ofconstruction without departing from the spirit of this invention. It is,therefore, to be understood that this invention is not to be limited tothe specific details described and shown.

Having thus described the invention, what is claimed is 1. The method ofcasting in a mold having metallic mold walls, comprising supplying aquantity of lubricant to the metallic walls of the mold through the saidwalls to prevent adhesion thereto of the material to be cast, andpouring the material to be cast into the mold and at the same timeallowing the gases to escape from the mold through the metallic walls ofthe mold.

2. The method of casting in a mold having metallic mold walls,comprising supplying a quantity of lubricant to the metallic walls ofthe mold through the said walls to prevent adhesion thereto of thematerial to be cast, and pouring the material to be cast into the moldand at the same time allowing the. gases to escape from the mold throughthe metallic walls of the mold below the level of the accumulatedmaterial within the mold.

3. The method of casting in a mold, which comprises supplying a quantityof carbon forming fluid to the wall of the mold cavity through the moldwall, and pouring molten metal into said-mold cavity after the carbonforming fluid has been supplied to the surface of the mold cavlty.

4. The method of casting in a mold, which comprises supplying a quantityof carbon forming fluid to the wall of the mold cavity through the moldwall, pouring molten metal into said mold cavity after the carbonforming fluid has been supplied to the surface of the mold cavity, andpermitting the gases to escape from the mold cavity below the level ofthe material as the material accumulates within the cavity.

5. The method of casting in a mold having metallic mold walls,comprising treating the walls of the mold with a lubricant to preventadhesion thereto of the material to be cast, and pouring the materialinto the mold while continuously supplying the lubricant to the walls ofthe mold below the level of the material as it accumulates in the mold.

6. The method of casting in a mold having metallic mold walls,comprising treating the walls of the mold with a lubricant to preventadhesion thereto of the material to be cast, pouring the material intothe mold while continuously supplying the lubricant to the walls of themold below the level of the material as it accumulates in the mold, andforcing the gases from the mold from below the level of the material asit accumulates in the mold.

7. The method of casting in a mold ,hav-

ing metallic mold walls, comprisingpouring, the material into the mold,and applying to the walls of the mold during the pouring of the materiala lubricant to prevent adhesion of the material to the mold.

8. The method of casting ,ina mold having metallic moldwalls,,comprising pouring material into the mold, and supplyingcontinuously to the walls of the mold at various points around thesurface thereof during the pouring of the material a lubricant toprevent adhesion of the material to the mold walls.

. 9. Thevmethod of casting in a mold hav-v ing metallic mold wallsprovided with lubricant supply passages through the walls thereof,comprising applying to the walls through said passages a lubricant toprevent adhesion of the material to the mold, and pouring the materialinto the mold.

10. The method of casting in a mold having metallic mold walls providedwith lubricant supply passages through the walls thereof, comprisingapplying to the walls of the mold through said passages, during thepouring of the material, a lubricant to pre-' vent adhesion of thematerial to the mold, and pouring the material into the mold.

11, The method of casting in a mold having metallic mold walls providedwith lubri-' cant supply passages through the walls thereof, comprisingapplying to the walls through said passages a lubricant to preventadhesion of the material to the mold, pouring the material into themold, and forcing the gases from within the mold through the mold wallsbelow the level of the material as it accumulates in the mold.

12. The method of casting in a mold having metallic mold Walls providedwith lubricant supply passages through the walls thereof, comprisingapplying to the walls of the mold through said passages during thepouring of the material a lubricant to prevent adhesion of the materialto the mold, pouring the material into the mold, and forcing the gasesfrom within the mold through the mold walls below the level of thematerial as it accumulates in the mold.

13. The method of casting metals in a mold having metallic mold walls,comprising applying a lubricant to the inner surface of the mold wallsthrough the Walls of the mold cavity, pouring the metal into the metalaccumulated in the mold, whereby the gases pass from the mold cavitybelow the level of the metal accumulated in the mold.

14. The method of casting metals, comprising pouring the metal into themold cavity, maintaining a lubricant outside of the mold cavity and incommunication with the cavity whereby the lubricant is supplied to thewalls of the mold cavity to preventadhesion-of the metal thereto, andventing the mold cavity at numerous points below the level of the metalaccumulated in the mold.

.15. The method of casting in a mold of metal or the like, comprisingpouring the material, while in a fluid condition, into a mold, andforcing the gases from the mold below the surface of the materialaccumulated in the mold, and at the same time maintaining a lubricantoutside of the mold and in communication with the mold cavity wherebythe lubricant is supplied to the Walls of the mold While the gases arebeing lated in the mold as the fluid accumulates in forced therefrom.the mold, and at the same time supplying a 16. The method of casting ina mold of lubricant to the Walls of the mold below the 10 metal or thelike, comprising pouring the level of the material accumulated therein.5 material, While in a fluid condition, into a In testimony whereof Iaffix my signature mold, and forcing the gases from the mold this 31stday of Ma ch, 1917. below the surface of the material accumu- FREDERICKHACHMANN.

